Sunday, December 21, 2008

Baby, It's Cold Outside

Winter officially arrived this morning about 6 AM. I was not up to greet it. Today is the shortest day of the year, barely nine hours from sunrise to sunset. With temperatures hovering around zero, winds gusting to about 28 miles per hour and 12-14 inches of snow on the ground, how can I not write about the weather?

According to this morning’s newspaper, the average low temperature for this date is 19 degrees F; the average high 33 degrees F. The record high was -14 F; the record high was 62 F. Although we are nowhere near the average, and it may be cold, this is somewhat normal for December in Wisconsin.

The harbor is frozen (that's ice and snow in the foreground of the picture) and the lake is, too, at least near the shore. It seems early to me for the lake to be frozen, so I looked around for data to support that claim.

What I found was a graph showing average Lake Michigan surface water temperatures. Data on the website are available from 1994, and the graph is current up to today. Yes, the water temperature this year is a little lower than normal, but in 2004, it was a little higher. I know five years isn’t much by way of statistical analysis, but if you just look at averages, we are in the right ballpark. There is still plenty of the lake that is not frozen, and just from my own observances in the past, as soon as the temperature goes up, the ice will disappear, and water will be visible again. The cycle repeats itself all winter, and so even without a thermometer, I can tell when the water is above or below 32 degrees F.

With all this cold, will I stay inside today? Yes, more than usual but not completely. I will walk the dog and then go to celebrate the first night of Chanukah. It’s one way to shed some light and warmth on a cold, short, wintry day.

Websites with maps of Great Lakes water temperature:

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